BioCycle January 2018
St. Paul, Minnesota: State DOT Issues New Compost Specs
The Minnesota Department of Transportation (MNDOT) updated its specifications for using finished compost in MNDOT projects in the 2018 Edition of its “Standard Specifications For Construction.” The two main changes to the specs, explains Kayla Walsh of the Minnesota Pollution Control Agency, are: 1) Inclusion of food waste as an approved feedstock for Grade II compost (for use as a landscape planting medium; Grade I compost is for use in turf establishment); and 2) Requiring that any finished compost made using food waste go through the US Composting Council’s Seal of Testing Assurance (STA) analysis to ensure safety and quality.
The Minnesota Composting Council (MN CC) has been advocating that all compost used by MNDOT meet the STA requirements, so is encouraged to see STA be introduced in this latest update. The Council, as part of its work plan to expand compost markets, also would like MNDOT to stop using the Grade I and Grade II labels and instead create parameters for composts based on their physical and chemical characteristics and the intended end use (e.g., project or soil type). To find the updated compost specifications, download the PDF of the 2018 specifications and scroll to pages 715 of the specs document or page 729 of the PDF document.
Charlotte, St. Thomas, U.S. Virgin Islands: Composting Versus Burning Hurricane Debris
As of early December 2017, the U.S. Army Corps of Engineers and the Federal Emergency Management Agency (FEMA) wanted to go ahead with a plan to incinerate 400,000 cubic yards of storm debris left behind on the U.S. Virgin Islands (USVI) by Hurricane Maria last September. Incineration is estimated to cost $5.2 million, compared to $5.3 million for mulching and $7.1 million for composting, according to the Army Corps and FEMA, which have proposed using air curtain incinerators — large metal bins with blowers that facilitate hotter, more complete burning. This plan is meeting resistance, however, due to a concerted effort by the elected officials, environmental organizations and health experts.
According to an excellent article in the online Inside Climate News (insideclimatenews.org), the USVI Senate passed legislation to ban the proposed burn in early December, and the Sierra Club and other environmental groups have threatened to sue the Corps and FEMA if they proceed with the incineration plan. The storm debris has been accumulated into large piles that are slowly composting, but the USVI lacks the funds to adequately manage the debris, according to Myron Jackson, President of the USVI Senate. Donald Caetano, a spokesperson for FEMA, told Inside Climate News that the agency has been authorized to fund 100 percent of the cost of debris cleanup from hurricanes Irma and Maria, regardless of the method chosen, and has already provided grants of more than $21 million to the territory for debris removal. Full funding for debris removal, however, expires six months after hurricanes Irma and Maria hit, meaning in March 2018. FEMA would cover only 90 percent of the cost for a second six months of debris removal, and after that would require a request for an extension, Caetano said.
Opponents of the incineration plan note it would further exacerbate health disparities in the predominantly black population where nearly one in four people lives below the federal poverty line. “Those opposed say the islands’ 100,000 residents are already choking on exhaust from diesel generators that are now pervasive across the territory, where more than half the population lacks electricity,” stated the article. Composting and wood recycling proponents released a vegetative debris management plan in November that outlines processing options, identifies potential sites for the organics recycling, and identifies markets for the compost and mulch. Ultimately, the decision on whether to burn or compost is up to the territory’s governor, Kenneth Mapp, who needs to decide whether to sign the legislation into law.
Judith Enck, a former U.S. Environmental Protection Agency Administrator for Region 2, which includes the USVI, has been researching costs to compost the vegetative debris, and assisting with development of a Request for Proposal for composting services. Enck was the EPA Regional Administrator when Hurricane Sandy struck the region in 2011, and told Inside Climate News that the Army Corps planned to use open-air incinerators for three to four months at Floyd Bennett Field in Brooklyn, New York, after Hurricane Sandy but aborted the effort after one month. “The decision to stop burning was in part because the devices violated air quality standards,” she recalled. “It’s completely unnecessary to be burning in the USVI when we have a viable composting alternative and also when the operation of these air curtain incinerators will pose such an air quality risk.”
Sierra Vista, Arizona: Organics Diversion At The Border
Approximately 2 million tons of produce cross the U.S.-Mexico border at Nogales, Arizona each year, comprising about 60 percent of all fresh produce in the U.S. from November to May, notes Chester Phillips, Sustainability Program Coordinator at the University of Arizona. “While the produce industry demonstrates remarkable efficiency in getting produce to market in good condition, waste remains a significant concern, with about 8,000 tons of produce ending up in just one Arizona landfill annually,” he explains. “Additional produce gets transported back across the border into Mexico to sell, and some gets dumped in Mexican landfills or illegally in the desert.” These circumstances, along with the need for nutrient-rich soil amendments for crop production, prompted the formation of a partnership between the University of Arizona (UA) Compost Cats, the Fresh Produce Association of the Americas, and Santa Cruz County (SCC) to develop a composting center in SCC.
“The SCC project will be modeled on the existing Compost Cats program of UA Cooperative Extension, a student-run composting operation that formed mutually beneficial partnerships with the City of Tucson, a Tohono O’odham Nation tribal farm, and Community Food Bank of Southern Arizona to address Tucson waste challenges,” adds Phillips. “The SCC Composting Center will expand on this partnership-driven model to provide green job and leadership training to Santa Cruz County high school and college students and build local capacity to confront complex environmental and social challenges.” The UA Compost Cats received a U.S. EPA Border 2020 Grant of $91,519 for the project, as well as a $10,000 Honorable Mention grant from the Rathmann Family Foundation’s “Mitigating Climate Change through the Use of Compost” Challenge Grant.
Nashville, Tennessee: Food Scraps Drop-Off Centers
The Metropolitan Government of Nashville and Davidson Counties has opened two drop-off centers for compostable food waste at existing recycling centers in the county using a grant from the Tennessee Department of Environmental Conservation. This program grew out of ongoing work by the Natural Resources Defense Council’s Nashville Food Waste Initiative and from an October 2017 Solid Waste Plan that showed 54 percent of landfilled solid waste was compostable.
Drop-off is free to residents. Materials can be put in a compostable bag, paper bag, small paperboard container (like ice cream boxes) or small cardboard box and dropped off at one of the centers. All food scraps, including meat, fish and dairy, and paper products such as soiled napkins, paper towels, paper plates and cups, are accepted. Households also can include cut flowers and household plants, dryer lint, hair and nail clippings, and pet food and pet hair.
East Lansing, Michigan: Compost Performance In Green Roof Substrate
A paper in Compost Science & Utilization (Vol. 25, No. 4, 2017) reports on an analysis of six green roof substrate blends that included compost, as compared to an unamended expanded shale aggregate. “Does Compost Selection Impact Green Roof Substrate Performance? Measuring Physical Properties, Plant Development and Runoff Water Quality,” authored by Jason M. Matlock and Dr. Bradley Rowe, determined the bulk density, field capacity, total porosity and saturated hydraulic conductivity for each substrate. The research includes a plant growth study conducted in a greenhouse using basil, sedum and bristleleaf sedge grown in all six substrates for six months.
The composts were made from a variety of organic feedstocks utilizing a variety of composting methods, e.g., hot composting at large commercial facilities, as well as lower temperature composting in small bins. Composts included: Yard G—screened yard trimmings compost produced in large windrows; Yard T—screened yard trimmings and horse manure compost produced in large windrows; Trans W—unscreened compost made from straw, pine shavings, hay, and sphagnum peat in pallet sized piles (water was used to soak materials prior to layering); Trans D—same materials and process as Trans W but used liquid waste fraction from an anaerobic digester for soaking feedstocks prior to composting; FWH—screened compost made from preconsumer food waste, leaf mold and wood chips and produced in static piles; and FWW—screened vermicompost produced in a wedge bed system in a high tunnel using same feedstocks as FWH. Runoff water was collected after simulated precipitation events on regular intervals during the plant growth study and analyzed for nitrate and phosphate concentrations.
Findings cited in the paper (which includes a wealth of data in tabular form) include:
• Nearly two-fold difference in dry biomass production among compost treatments for all 3 plant species. Growth rates varied by a factor of 2.6, 1.9 and 1.5 for basil, sedum and bristleleaf sedge, respectively. These results suggest that compost selection can have a strong effect on the initial establishment of a green roof, both in terms of size of plants and area they cover.
• Differences in how the compost is produced, for example, a traditional hot compost method (FWH) versus a vermicompost method with lower temperatures (FWW) demonstrated how changes in compost production translate to substrate performance.
• Compost selection had a strong impact on initial nitrate and phosphate concentrations, but the influence of compost on concentrations diminished with time.
• A clear linkage was seen between soluble nutrient concentrations in compost and short-term mass loading of those nutrients in runoff water. However researchers saw that use of plant species with greater nutrient and water demands, such as basil, significantly reduced mass loading. “Thus, plant selection and acceptable compost nutrient levels go hand-in-hand,” conclude the authors.